Is New Hampshire about to flip the script for Hillary Clinton and Bernie Sanders?

Story highlights

  • David Axelrod: 2008 New Hampshire primary instructive:
  • In 2008, Obama, newly victorious coming out of Iowa, lost to Clinton, who N.H. voters saw as underdog
  • Axelrod: Campaigns can't take anything for granted in New Hampshire

David Axelrod is CNN's senior political commentator and host of the podcast "The Axe Files." He was senior adviser to President Barack Obama and chief strategist for the 2008 and 2012 Obama campaigns. The opinions expressed in this commentary are his.

Manchester, N.H. (CNN)We landed in Nashua before dawn, a conquering political army arriving in New Hampshire to negotiate the terms of surrender.

Hours earlier, Barack Obama had won a stunning victory in the 2008 Iowa caucuses and the putative nominee, Hillary Clinton, had placed a disappointing third. Now we had a chance for a quick knockout. Two straight wins and the nomination battle effectively would be over.
But even as Obama was triumphantly crisscrossing New Hampshire, the state's famously contrarian voters were preparing to rewrite the script.
    Five days before the primary, Obama was leading Sen. Clinton and a field of other challengers by a gaudy double-digit margin. The Sunday before the Tuesday primary, our own polling showed us ahead by eight.
    But on primary day, Hillary was resuscitated by the voters of New Hampshire with a two point upset victory.
    The message for campaigns here?
    Don't take anything for granted in the Granite State.
    In those final days before New Hampshire voted in 2008, Clinton and Obama suddenly swapped places in the minds of the state's voters. After a year as David taking on Clinton's Goliath, Obama was now abruptly transformed into the behemoth by the voters of Iowa.
    And after a year spent cautiously posed atop the frontrunner's pedestal, Hillary Clinton became the plucky challenger, fighting against the conventional wisdom that Obama was now the certain nominee.
    Clinton proved a more compelling underdog than frontrunner, campaigning with heart and conviction, and achieving a connection to people that she had lacked before. Her struggle became their struggle.
    The upstart Obama may have had apparent advantages, but New Hampshire voters gave him his comeuppance ... and Clinton new life. They simply weren't ready to proclaim the young phenom, just three years removed from the Illinois state senate, the de facto nominee of the Democratic Party.
    Five days before this year's first-in-the-nation primary, the scene in New Hampshire is very different. Clinton is Goliath -- once again the presumptive nominee -- and a heavy underdog in New Hampshire.
    Having squeaked by Sen. Bernie Sanders in Iowa, and with big leads in the polls in the more diverse states that follow, she does not need a win here and probably won't get one.
    The widely held belief that she will be the nominee may work against her in New Hampshire, just as it did Obama eight years ago.
    For those who admire his progressive purity and populist thunder, a vote for Sanders carries little risk. They figure they can send a message now, and vote for Clinton later. But if Sanders were to be upset here, which few expect, his future as a genuine challenger for the nomination would be badly damaged. For all intents and purposes, the race would be over.
    Voters here are accustomed to playing the role of referee, deciding the candidates who will go on and relegating others to the sidelines.
    Given lingering questions about Clinton's sometimes prosaic style on the stump and the assorted baggage she's accrued, they likely aren't ready to end the fight.
    New Hampshire also is a vastly different battleground than Iowa.
    Because undeclared or independent voters -- the largest single bloc at about 44 % -- can participate in either party's primary, they have a disproportionate influence over the result. So candidates are not only contending with their primary opponents for party loyalists, but also with candidates in the other party for the support of these free agent "undeclared" voters.
    In 2000, a wave of undeclared voters migrated to the Republican primary to help John McCain defeat George W. Bush. This undercut the insurgent Democratic campaign of Bill Bradley, who was counting on these independent voters to help him sink frontrunner Al Gore. While McCain buried Bush by 18 points, Gore narrowly defeated Bradley, defusing a challenge that would soon fade away.
    Sanders is not only appealing to independents, he has been one for his entire political career. Though he sits with the Democrats in the Congress, this is the first time that he has sought the Democratic nomination for any office.
    In Iowa, Sanders defeated Clinton among the self-identified independents who signed up for the Democratic caucuses, winning over 70%. And New Hampshire polling suggests he is doing almost as well with undeclared voters here.
    But what we don't know is where the nomadic "undeclareds"-- especially those who have a history of party switching from election to election -- will land in a year when the reality show that is the Republican race has garnered so much attention.
    If these voters believe, as the polls suggest, that Sanders is a sure winner, many may head over to the GOP, where Donald Trump has an appeal to independents, and Gov. John Kasich of Ohio has quietly, but relentlessly worked them. This could narrow Sanders' margin.
    But the senator from Vermont has a significant lead and should win here Tuesday, despite -- and maybe because of -- the heavy presumption in Hillary Clinton's favor.
    As some of us learned in 2008, New Hampshire likes to write its own story.